Laser diode (LD) and inorganic light emitting diode (LED) known as the light emitting device are well known as exposure light sources for writing on a photographic material. However, the emission wavelengths of LD and LED cannot be changed easily, in particular, there is almost no room of selection in the wavelength of blue light emitting device. The organic light emitting device has been eagerly studied since 1980 due to the advantage of a thin film light emitting device and the use as the exposure light source has been discussed. For example, as disclosed in JP-A-7-22649 (the term "JP-A" as used herein means an "unexamined published Japanese patent application"), it has been suggested to use the organic light emitting device for exposure of generally commercially available photographic films and films for instant cameras by means of a photorecording apparatus provided with a plurality of lines of organic light emitting devices arranged in dot array classified by luminescent colors. The organic light emitting device is easy to obtain arbitrary emission spectrum and arrange in dot array, and design with less moving parts is practicable, therefore, it can be preferably used as an exposure light source.
However, in a silver halide photographic material having at least three spectral sensitivities in the radiant rays of the region of from 400 to 900 nm, the emission spectrum of the exposure light source is particularly important, and there are problems that when exposure is performed using ordinary organic light emitting devices having broad half band widths, color turbidity (a negative photographic material) or color blank (a positive photographic material) are generated, and color reproduction of the image is deteriorated. It has been found that this phenomenon is attributed to the fact that when silver halide is spectrally sensitized with a sensitizing dye, a sensitivity peak acutely descending is generally formed on the longer wavelength side not on the short wavelength side, on the other hand, when an organic light emitting device is used, the emission spectrum is generally steep on the short wavelength side not on the long wavelength side.